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Water lentils approved as a vegetable in the EU

Water lentils have received approval from the European Food Safety Authority (EFSA) for production and consumption as fresh vegetable in the EU.

It has been a long process for researchers from Wageningen University & Research (WUR) in the Netherlands to secure this approval – nearly 10 years of research, in fact.

This included building and submitting a novel food dossier to EFSA to prove water lentils’ safety, nutritional value, and sustainable cultivation.

Water lentils: The new and sustainable green on the block

Water lentils (or duckweed) are small green aquatic plants that naturally grow on the surface of slow-moving or stagnant water, such as lakes and ponds. The plants can also be cultivated in closed environments and therefore have potential to be grown commercially using sustainable farming methods including greenhouses and or vertical farming.

As the plants grow on water, there is no need for agricultural land, high amounts of fertilisers, or excessive water use. The plant grows rapidly, in a manner similar to yeast, splitting into two every three to four days, then splitting again into four plants. While this means harvesting needs to happen around once to twice per week, it also means high yields per hectare per year.

Not only is the plant a sustainable crop, but it also offers an alternative to traditional food sources, supporting the global transition towards a more plant-based food system.

Water lentils are high in vitamins, minerals and carotenoids, and have an essential amino acid profile that fits the recommendation of the World Health Organization for children aged six months and above.

Water lentils categorised as novel food by EFSA

Despite their potential, water lentils, until now, had not been approved in the EU. Without EFSA approval, they could not legally be produced and sold for human consumption.

The team at WUR, led by senior researcher and bioscience department head Ingrid van der Meer – the initiator behind this research – sought to change this. Van der Meer told Ingredients Network that while the trajectory to EFSA approval is long, it is important.

“I think it's very good that we have these rules and legislation. Everything that was not eaten at a high extent before 1997 is seen in Europe as a novel food, and then if you want to put it on the market for human consumption, you need to submit a dossier with all the scientific and technological evidence showing that indeed it can be produced in a very hygienic way, is safe to eat, and can be digested by humans,” she explained.

EFSA approval process and novel food dossier

After compiling a dossier demonstrating the safety, sustainability, digestibility, and nutritional properties of water lentils, the team at WUR submitted it to EFSA for approval.

After several years, and plenty of back and forth between WUR and the EFSA committee –including additional questions and answers that required new research and results – EFSA considered everything to be safe, except for the manganese levels in the plant, which were deemed too high to be safely approved.

This led WUR to submit an additional report with scientific evidence, showing that slight modifications to the cultivation methods could lower manganese content in the plants to below the limit set by EFSA, 6 mg/kg.

In July 2024, EFSA granted approval, then it took an additional six months for the approval to be put into EU legislation.

The current EFSA approval is for two of the 36 species of water lentils, and the approval covers their use as a vegetable only. Van der Meer explained that drying the ingredient and selling it as a powder is not accepted, adding that twice, a company has attempted to gain approval for dried duckweed; however, both applications were rejected by the EFSA.

“There is about 95% water in the fresh plants. So, if you dry it, you really concentrate all the minerals that are present,” she said, explaining that this elevates mineral levels to unapproved limits.

Are consumers willing to get on board?

Water lentils, while not considered a staple food in Southeast Asia, are still widely consumed – while in the West, they are unfamiliar to consumers. To become a mainstream and sustainable food, consumer acceptance is just as important as regulatory approval.

However, here lies a problem. Food companies are hesitant to invest as they need reassurance that consumers will be interested, while consumers, in theory, can only be interested in, and demand a product once it is available.

Van der Meer sees it as “chicken and egg situation”. As of February 2025, no high-scale commercial cultivation in the EU has begun.

WUR has conducted consumer testing to understand how water lentils would be received on the European market. The testing included taste preferences, perceptions, and likelihood of adoption.

In the taste trials, volunteer participants tried soup, mashed potatoes, quiche, lasagna, pasta, and risotto containing water lentils. Initial responses were that the taste was unfamiliar.

However, after one day, many grew accustomed to the novel taste, and rated the dishes favourably, some even preferring water lentil soup over spinach-based soup.

WUR also conducted interviews and surveys with over 1,000 respondents, measuring the acceptability of water lentils in European diets. The results indicated a positive trend in consumer interest, but the researchers emphasised the importance of education around water lentils’ benefits to both planetary health and sustainability.